Closure device of plastic for tubes and containers

ABSTRACT

A closure device of plastic which comprises a cap which is to be fitted over and pressed upon the open end of a container and carries on the inside of its top a resilient hollow plug which is inserted into the open end of the container and has one or more locking projections which snap into an inner annular groove in the container wall or over an annular projection on this wall when the cap seals the container tightly. For unlocking the plug from the container wall to permit the cap to be withdrawn, a central part of the top is depressed, whereby a central stem at the inside of the plug effects a deformation of the plug so that the locking projection of projections of the plug are retracted from the annular groove or projection of the container wall.

United States Patent CLOSURE DEVICE OF PLASTIC FOR TUBES AND CONTAINERS7 Claims, 8 Drawing Figs.

Int. Cl .Qf. 865d 39/12 Field of Search 215/52- Primary Examiner-GeorgeT. Hall Anorney- Flynn and F rishauf ABSTRACT: A closure device ofplastic which comprises a cap which is to be fitted over and pressedupon the open end of a container and carries on the inside of its top aresilient hollow plug which is inserted into the open end of thecontainer and has one or more locking projections which snap into aninner annular groove in the container wall or over an annular projectionon this wall when the cap seals the com tainer tightly. For unlockingthe plug from the container wall to permit the cap to be withdrawn, acentral part of the top is depressed, whereby a central stem at theinside of the plug effects a deformation of the plug so that the lockingprojection of projections of the plug are retracted from the annulargroove or projection of the container wall.

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CLOSURE DEVICE F PLASTIC FOR TUBES AND CONTAINERS The present inventionrelates to a closure device for tubes, cans, bottles or othercontainers, and more particularly to such a device which may be usedrepeatedly for tightly closing and opening the mouth of the respectivecontainer or of any other container which has a mouth of the same size.

Among the multitude of such closure devices as were disclosed prior tothis invention there are some which are of such a complicatedconstruction that their manufacture renders them too expensive, whileothers are so difficult to manipulate as to be impractical. Thoseclosure devices, however, which are of a more simple type are usuallynot sufficiently secure, especially for rescaling a container after ithas once been opened. All of the known closure devices of theabove-mentioned type have the further disadvantage that they may beopened only by applying considerable force or by means of rathercomplicated manipulations.

It is an object of the present invention to provide a closure device ofthe type as first mentioned above which is made of plastic and may bemanufactured at a relatively low cost and be manipulated very easily foropening and tightly closing a bottle, can, tube or other container andmay also be used repeatedly with the same effect on the same containeror in different containers with mouths of the same size.

The closure device according to the invention comprises a cap which isadapted to be fitted over the open end oftlie container and has a sidewall for surrounding the upper endportion of the container and a top orcover for closing theopen end. This cover may be either resilient anddirectly secured to or integral with the side wall of the cap or it mayform an element separate from the cap which is inserted into a centralaperture in a top wall of the cap and is guided therein so as to bemovable in the axial direction of the cap. The closure device furthercomprises a resilient hollow plug. which has a substantiallydouble-conical shape, that is, substantially the shape of two hollowcones which are joinedto each other at their common base. This plug hasone end eormected or secured to the inner side of the top wall ofthe capand-due-to its own resilience and its particular shape it has thetendency to expand uniformly in all radial directions at its widestport, that is, at the mentioned base of the two cones. At this part, theplug is provided with a small annular outwardly projecting rim. When thecap is fitted over the open end of a container, this plug will at thesame time engage into the open end, and when the cap is presseddownwardly so far that a resilient sealing surface either on the topwall of the cap or on the part of the plug which is secured to the capis compressed and tightly closes the open end of the container, theprojecting rim snaps downwardly over a small annular projection on theinner wall of the container or into an annular recess in this wall andthereby locks the cap securely in its sealing. position on thecontainer.

For unlocking and removing the cap. the resilient cover of the latter orthe separate cover element is connected to thelower end of the hollowplug by means of a central stern. lfthe resilient cover or the coverelement is depressed from above, the stern will transmit this movementto the lowercnd ofthe hollow plug. The plug will thereby be extendedtoward the inside of the container and the locking; rim of the plugwillthereby be radially contracted and pulled out of its engagement with theannular recess in the wall of the container or with the annularprojection on this wall, whereupon the cap may be pulled off the upperend of the container. If this stem is firmly secured at its oppositeends to the cover or cover'element and to the lower end of the hollowplug. it will serve as a means for preventing the cap from being pulledoff 'the container by force. If such an attempt is made; whilethe coveror cover element is not also depressed, even the slightest traction uponthe cover will be transmitted by the stem to the lower even more firmlyinto the locking recess or against the locking projection of thecontainer wall.

According to another embodiment of the invention, the hollow plug whichmay have a general shape like the plug as previously described isdivided into a plurality of segments which are secured to or integralwith each other at their upper ends but are separate from each otherdown to their lower ends. At the maximum diameter of this plug, thesegments are provided with equal outer locking projections whichtogether correspond to the locking rim of the plugs as previouslydescribed. The central stem is secured at its upper end to the cover orcover element of the cap and its lower end projects through the separatelower ends of the segments which abut A against its peripheral surfacewithout being secured thereto. A

short distance above the point of engagement of the lower ends of thesegments with the stem, the latter is provided with an annular recess.When the cover or cover element is depressed for a certain distance, thelower end of the stem passes through the lower ends of the segmentsuntil the latter snap into the annular recess in the stem and therebycontract the locking projections which are thus withdrawn from thelocking-recess in the wall of the container or from the lockingprojection on this wall so that the cap may then be withdrawn from theend of the container. Apart from the fact that the plug according tothis embodiment of the invention might be more easily produced than theone-piece plug as previously described, it also has the advantage thatan accidental pressure upon the cover or cover element of the cap willnot immediately cause the locking rim of the plug to be contracted andwithdrawn from the annular recess or the annular projection of thecontainer wall, but that a greater pressure upon the cover or coverelement will be required so as to shift the stem until the lower endswill engage into the annular recess of the stem.

From the previous description it is evident that a mere pull upon thecap will not remove it from the container unless a certain downwardpressure is exerted at the same time upon the cover or cover element ofthe cap. Turning the cap in one direction or the other about its axiswill not effect or facilitate its removal. The closure device accordingto the invention has the additional advantage that an increase of theinternal pressure of the material in the container acts upon the lowerside of the plug and increases the locking action of the plug upon thewall of the container.

The entire closure device according to the invention may be made of arelatively stiff plastic which, however, is sufficiently resilient forattaining a good sealin'g effect and to permit the same device to beused many times.

The features and advantages of the present invention will become furtherapparent from the following description chereofwhich is to be read withreference to the accompanying drawings, in which:

FIG. to shows a central longitudinal section of the new closuredeviceaccording to one embodiment of the invention;

FIG. 1b shows the device according to FIG. la partly in section andpartly in a side view;

FIG. It: shows a longitudinal section of a part of a closure devicesimilar to that as shown in FIGS. la and 1b, but in loclting engagementwith a container with an annular inner projection;

FIG. 25: shows a longitudinal section ofa' closure device accordingto amodification of the invention;

FIG. Zhshows a longitudinal section of a closure device according'toanothermodification of the invention;

FIG. 3a'sli'ows a longitudinal section of a closure device accordingto afurther modification of the invention;

HG. shows partly in section and partly in a side view substantially thesame closure device as shown in FIG. 30, but in lookingengagement'with acontainer with an annular inner projection; while FIG. 3:- shows alongitudinal section of a part of the same part of the plug and willcause the locking 'rim to be pressed closuredevice asshown in FIG. 3b.

The closure device as shown in FIGS. 10, lb and 1c of the drawingscomprises a cap 1 of plastic the cover part of which is resilient andintegral with its sidewall. A hollow resilient plug 4 which is likewisemade of plastic has a substantially double-conical shape which has onits upper end an outwardly projecting part 7 which is firmly connectedto the cap 1 2 and is provided with an annular downward projection 6which is adapted to engage with the inner side of the open mouth of thecontainer 8 and to serve as a sealing gasket for closing the mouth. Theupper and lower. cones of plug 4 have the tendency to move toward eachother and thereby to enlarge the diameter of their common base. At thisbase, plug 4 is provided with a small annular outwardly projecting rim 5which, when the cap is fitted over and pressed down upon the mouth ofthe container 8 and the plug 4 is at the same time inserted into themouth, snaps either into an annular recess 9 in the wall of thecontainer, as shown in FIGS. la and lb, or over an annular projection 9on this wall, as shown in FIG. 1c, and thereby locks the cap in itssealed position.

In order to permit the plug 4 to be unlocked from the container wallwhen the cap 1, 2 together with the plug is to be withdrawn from thecontainer 8, a central stem 3 is provided at the inside of the plug andeither connected or secured at its enlarged opposite ends to the coverpart 2 and the lower end of plug 4. When the resilient cover part 2 isdepressed, the lower end of the stem 3 presses the lower part of plug 4downwardly and thereby elongates the plug which causes its projectingrim 5 to be contracted and thereby pulled out of the annular recess 9 inthe container wall, as shown in FIGS. la and lb, or out of engagementwith the annular projection 9' on this wall, as shown in FIG. 10. If thecap 1, 2 is at the same time pulled upwardly, the entire closure devicemay be easily removed from the container.

The closure device as illustrated in FIG. 2a differs from the deviceaccording to FIGS. la, b and c primarily by the provision of a separatecover element 2' to which the upper end of the central stem 3 isconnected and which is inserted into an aperture 10 in the top wall ofcap 1 and guided by the wall of this aperture. Annular shoulders on thiswall prevent the cover element 2 from being pushed upwardly ordownwardly out of the aperture 10. This closure device differs furtherfrom that as shown in FIGS. 1a, b and c by the fact that the plug 4 doesnot form an element separate from the cap 1 but that it is integral withthe cap. The annular sealing projection 6 is therefore likewise integralwith cap 1. The lower end of stem 3 is rigidly secured to the center ofthe lower end of plug 4, and along the line of its greatest diameter theplug is again provided with an annular outwardly projecting rim 5 whichis adapted to engage into an annular recess 9 in the container wall 8.The operation and the effect of the closure devices as shown in FIGS.la, b and c and in FIG. 2a, respectively, are practically the same.However, while the cover part 2 of cap I of the first closure devicewhich is integral with the cap must be resilient, the separate coverelement 2' of the cap of the second closure device may be rigid since itis guided in the axial direction by the wall of the aperture 10.

The closure device as shown in FIG. 2b differs from the device accordingto FIG. 2a merely by the shape of plug 4 and by the manner of connectingthe lower end of the stem 3 to the lower end of the plug.

H68. 30, b and 0 illustrate a further embodiment of the invention inwhich the hollow plug consists of a plurality of segments 4' which areintegral at their upper ends with an outwardly projecting sealing part 7similar to that as shown in FIGS. la, b and c, while their lower innerends 11 are not secured to each other. Segments 4 are molded so as tohave the tendency to bend radially toward the central axis of the cap.At the maximum diameter of the plug, all of the segments 4' are providedwith locking projections 5' which are disposed at the same level. Theupper end of the central stem 3' is rigidly secured to the resilientcover part 2 which is integral with the side wall of cap I, and thelower cylindrical end portion 12 of the stem projects downwardly betweenand beyond the separate lower inner ends 11 of the segments 4' which,due to their tendency to bend toward the central axis of the cap, abutagainst the endportion 1'2. 'Due to this pressure of the end portion 12against the ends 11 of the segments, the maximum diameter of the plug.that is, the diameter of the locking projections 5', is increased sothat, when the cap I, 2 is applied over the open end of the container 8;and the plug segments 4' are at the same time inserted into the mouth ofthe container, the segments will at first be compressed until the cap ispressed down so far that the mouth of the container will be tightlysealed by the gasket or sealing part of the plug, at which time thelocking projections 5' of the segments will snap into the annular recess9 or over the annular, preferably rounded projection 9" of the containerwall 8 and thus lock the cap I, 2 in its sealing position.

For unlocking the plug so as to permit the cap I, 2 to be withdrawn fromthe mouth of the container, the central stem 3' is provided above theend portion 12 with an annular recess 13 of a depth substantially equalto the depth of the annular recess 9 or the horizontal thickness of theannular projection 9" of the container wall 8. When the resilient coverpart 2 is depressed for a sufficient distance, the lower inner ends 11of the plug segments 4' will snap into this recess 13 and the lockingprojections 5' will thereby be withdrawn from the recess 9 or theprojection 9" of the container wall so that the entire closure devicemay then be easily withdrawn from the container.

While the entire closure device consists of relatively tough plastic andis preferably produced by injection molding, its plug part 4 or 4' ismolded so as to exert a relatively strong spring action. The closuredevice may then be employed for a very long time for opening and tightlyclosing a container with a mouth of an appropriate size or differentcontainers all of which have a mouth of such a size.

Although our invention has been illustrated and described with referenceto the preferred embodiments thereof, we wish to have it understood thatis in no way limited to the details of such embodiments but is capableof numerous modifications within the scope of the appended claims.

Having thus fully disclosed our invention, what WE claim is:

l. A closure device of plastic for tubes, cans, bottles or othercontainer each having a locking part formed by an annular recess in oran annular projection on the inner wall of the container wall near theopen mouth of the container, said device comprising a cap having a topwall, the central part of said wall being adapted to be resilientlydepressed, gasket means for tightly sealing said mouth when said cap ispressed thereon, a hollow resilient plug of a substantiallydouble-conical shape having one end connected to said top wall andhaving an annular outwardly projecting locking rim at the level of themaximum diameter of said plug, said rim being adapted to snap intolocking engagement with said locking part of said container wall whensaid plug is inserted into said mouth and said plug is pressed down soas to be in tight sealing engagement with said mouth, and a central stemconnected to said top wall and adapted when said top wall is depressedto act upon the lower part of said plug so as to deform said plug insuch a manner that said projecting rim is contracted and withdrawn fromsaid locking part of said container wall so that said entire device maythen be withdrawn from said container.

2. A closure device as defined in claim I, in which the upper end ofsaid central stem is firmly secured to said top wall of said cap.

3. A closure device as defined in claim I, in which the upper end ofsaid central stem is firmly secured to said top wall of said cap and itslower end to the lowest part oi said plug.

4. A closure device as defined inclaim 1, in which said top wall of saidcap has a central aperture, and a separate cover disk inserted into saidaperture and guided by the wall thereof for a limited upward anddownward movement in the axial direction of said cap, the upper end ofsaid stem being connected to said cover disk.

5. A closure device as defined in claim I, in which said gasket meansare formed by the upper end portion of said plug which is connected tosaid top wall of said cap.

6. A closure device as defined in claim 4, in which said gasket meansare formed by the upper end portion of said plug which is integral withthe part of said top wall surrounding said cover disk.

7. A closure device as defined in claim I, in which the part of saidplug which is to be inserted into said container is divided into aplurality of segments each having a projecting edge at the same level sothat said edges together form said locking rim, said segments extendingdownwardly from said edges and toward the central axis of said cap andtending to bend resiliently toward said axis so as to retract said edgesfrom said locking part of said container wall, said stem being rigidlysecured at its upper end to said top wall and adapted to be depressedthereby, said stem having a lower end portion extending between and inabutting engagement with the loose lower ends of said segments so asnormally to maintain said locking rim at its maximum locking diameter,said stem having an annular recess above said lower end portion having adepth substantially equal to the depth of said locking part so that,when said top wall is sufficiently depressed. said lower ends of saidsegments slide along said lower end portion of said stem, then engageinto said recess and move resiliently toward each other, whereby thediameter of said locking rim decreases and said rim disengages from saidlocking part of said container wall so that said entire device may thenbe withdrawn from said container.

1. A closure device of plastic for tubes, cans, bottles or othercontainer each having a locking part formed by an annular recess in oran annular projection on the inner wall of the container wall near theopen mouth of the container, said device comprising a cap having a topwall, the central part of said wall being adapted to be resilientlydepressed, gasket means for tightly sealing said mouth when said cap ispressed thereon, a hollow resilient plug of a substantiallydouble-conical shape having one end connected to said top wall andhaving an annular outwardly projecting locking rim at the level of themaximum diameter of said plug, said rim being adapted to snap intolocking engagement with said locking part of said container wall whensaid plug is inserted into said mouth and said plug is pressed down soas to be in tight sealing engagement with said mouth, and a central stemconnected to said top wall and adapted when said top wall is depressedto act upon the lower part of said plug so as to deform said plug insuch a manner that said projecting rim is contracted and withdrawn fromsaid locking part of said container wall so that said entire device maythen be withdrawn from said container.
 2. A closure device as defined inclaim 1, in which the upper end of said central stem is firmly securedto said top wall of said cap.
 3. A closure device as defined in claim 1,in which the upper end of said central stem is firmly secured to saidtop wall of said cap and its lower end to the lowest part of said plug.4. A closure device as defined in claim 1, in which said top wall ofsaid cap has a central aperture, and a separate cover disk inserted intosaid aperture and guided by the wall thereof for a limited upward anddownward movement in the axial direction of said cap, the upper end ofsaid stem being connected to said cover disk.
 5. A closure device asdefined in claim 1, in which said gasket means are formed by the upperend portion of said plug which is connected to said top wall of saidcap.
 6. A closure device as defined in claim 4, in which said gasketmeans are formed by the upper end portion of said plug which is integralwith the part of said top wall surrounding said cover disk.
 7. A closuredevice as defined in claim 1, in which the part of said plug which is tobe inserted into said container is divided into a plurality of segmentseach having a projecting edge at the same level so that said edgestogether form said locking rim, said segments extending downwardly fromsaid edges and toward the central axis of said cap and tending to bendresiliently toward said axis so as to retract said edges from saidlocking part of said container wall, said stem being rigidly secured atits upper end to said top wall and adapted to be depressed thereby, saidstem having a lower end portion extending between and in abuttingengagement with the loose lower ends of said segments so as normally tomaintain said locking rim at its maximum locking diameter, said stemhaving an annular recess above said lower end portion having a depthsubstantially equal to the depth of said locking part so that, when saidtop wall is sufficiently depressed, said lower ends of said segmentsslide along said lower end portion of said stem, then engage into saidrecess and move resiliently toward each other, whereby the diameter ofsaid locking rim decreases and said rim disengages from said lockingpart of said container wall so that said entiRe device may then bewithdrawn from said container.